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Biomedical subjects

Y Saitoh

Publications and source records attributed to Y Saitoh.

At least 109 records · Page 6Linked to original sources
PubMed2000

Balloon-occluded endoscopic retrograde ileography.

For diagnostic ileography, the authors developed balloon-occluded endoscopic retrograde ileography and performed 77 studies in 36 consecutive patients with Crohn disease. Balloon-occluded endoscopic retrograde ileography proved to be useful in visualization of minute mucosal lesions such as aphthous ulcers and lymphoid hyperplasia in the distal ileum, and satisfactory ileographic images of Crohn disease were obtained in 54 (70%) studies.

Adolescent↗
PubMed2000

Pneumoconiosis-related lung cancers: preferential occurrence from diffuse interstitial fibrosis-type pneumoconiosis.

It has been reported that patients with pneumoconiosis occasionally have a diffuse interstitial fibrosis (DIF) that resembles interstitial pneumonia, but little is known about the relation between pneumoconiosis-associated DIF and the risk of lung cancer. In the present study, we evaluated the incidence of DIF by chest CT and its contribution to lung cancer in 563 patients with nonasbestos pneumoconiosis. Fifty-five (10%) of the 563 patients had DIF. Pneumoconiosis with DIF had an exceedingly high concurrence of lung cancers when compared with pneumoconiosis without DIF (29 [53%] of 55 versus 78 [15%] of 508, p < 0.001). Squamous cell carcinomas (SCCs) of the lung from pneumoconiosis with DIF exclusively comprised peripheral-types, as compared with SCCs from pneumoconiosis without DIF (13 [100%] of 13 versus 33 [72%] of 46, p = 0.03). In addition, lung cancers arose frequently from the area of DIF in pneumoconiosis with DIF (20 [74%] of 27). Furthermore, our pathologic examination revealed that dysplasias from pneumoconiosis with DIF were significantly more frequently observed in peripheral bronchioli than were dysplasias from pneumoconiosis without DIF (11 [69%] of 16 versus 20 [30%] of 66, p = 0.01). p53 expression evaluated by immunohistochemistry was frequently observed in dysplasias from pneumoconiosis with DIF, although it was not significantly different compared with that in dysplasias from pneumoconiosis without DIF (5 [50%] of 10 versus 12 [38%] of 32). Taken together, these results may suggest a positive causal relationship between pneumoconiosis and peripheral-type SCCs of the lung, and further indicate a pivotal role of diffuse fibrosis for the excess incidence of lung cancers, especially peripheral-type SCCs, in DIF-type pneumoconiosis.

Aged↗
PubMed2000

N-methyl D,L-aspartate induces the release of luteinizing hormone-releasing hormone in the prepubertal and pubertal female rhesus monkey as measured by in vivo push-pull perfusion in the stalk-median eminence.

The role of the excitatory amino acid glutamate, N-methyl D-aspartate (NMDA) receptor agonist, in stimulating in vivo luteinizing hormone-releasing hormone (LHRH) release in the stalk-median eminence of conscious prepubertal and pubertal female rhesus monkeys was evaluated using push-pull perfusion. In Exp 1, the effects of i.v. bolus injection of N-methyl D,L-aspartate (NMA) on LHRH release were examined. Injection of NMA induced an increase in LHRH release in all maturational stages of monkeys. Although the LHRH response to NMA tended to be larger in the older groups, only the duration of the LHRH response in the midpubertal group was significantly longer than that in the prepubertal group. In Exp 2, the effects of direct infusion of NMA (0.1, 1, and 100 microM) into the stalk-median eminence on LHRH release were similarly examined. NMA infusion stimulated LHRH release in pubertal monkeys, whereas it did not induce any consistent changes in LHRH release in prepubertal monkeys except for the highest dose. These data suggest that: 1) the systemic injection of NMA is more effective than direct infusion of NMA; and 2) the prepubertal LHRH neurosecretory system is capable of responding to NMDA, although the responsiveness may undergo developmental changes. Therefore, stimulation of NMDA receptors may contribute to the pubertal changes in the LHRH neurosecretory activity.

Animals↗
PubMed2000

Comparative study of superoxide dismutase in normal and hereditary cataract (UPL) rats.

In the present study, the levels of SOD activity and Cu, Zn-SOD mRNA in the brain, kidney, liver and eye of normal and Upjohn Pharmaceutics Limited (UPL) rats, a new hereditary cataract model derived from Sprague-Dawley rats, were measured. Although the levels of SOD activity in the eye and brain of UPL rats were significantly decreased compared with those of normal rats 3 and 5 weeks after birth, the levels of SOD activities in the kidney and liver were the same in both groups. The levels of Cu, Zn-SOD mRNA in kidney and liver of UPL rats were the same as those of normal controls. The level of Cu, Zn-SOD mRNA in the brain of normal rats 5 weeks after birth was about twofold greater than that of UPL, and that in the eye of UPL rats 3 weeks after birth was significantly decreased compared with that of normal controls. The sequences of cDNA encoding Cu, Zn-SOD and the sequences of the regulatory region of the Cu, Zn-SOD gene were confirmed to be the same in normal and UPL rats. These results indicated that the decreases in levels of SOD activity and Cu, Zn-SOD mRNA in the brain and eye of UPL rat were not due to mutation of the genomic Cu, Zn-SOD gene in UPL rats or differences in the sequence of the regulatory region of the Cu, Zn-SOD gene between normal and UPL rats.

Animals↗
PubMed2000

Motor cortex stimulation for central and peripheral deafferentation pain. Report of eight cases.

The authors tested a modified motor cortex stimulation protocol for treatment of central and peripheral types of deafferentation pain. Four patients with thalamic pain and four with peripheral deafferentation pain were studied. Preoperative pharmacological tests of pain relief were performed using phentolamine, lidocaine, ketamine, thiopental, and placebo. In five patients we placed a 20- or 40-electrode grid in the subdural space to determine the best stimulation point for pain relief for a few weeks before definitive placement of a four-electrode array. In three patients, the four-electrode array was implanted in the interhemispheric fissure as a one-stage procedure to treat lower-extremity pain. In two patients with pain extending from the extremity to the trunk or hip, dual devices were implanted to drive two electrodes. Six of eight patients experienced pain reduction (two each with excellent, good, and fair relief) from motor cortex stimulation. No correlation was apparent between pharmacological test results and the effectiveness of motor cortex stimulation. Patients with peripheral deafferentation pain, including two with phantom-limb pain and two with brachial plexus injury, attained pain relief from motor cortex stimulation, with excellent results in two cases. Testing performed with a subdural multiple-electrode grid was helpful in locating the best stimulation point for pain relief. Motor cortex stimulation may be effective for treating peripheral as well as central deafferentation pain.

Aged↗
PubMed2000

[An office technique for myringoplasty without the use of fibrin glue].

A simple method for office closure of eardrum perforation using an atero-collagen graft used for dermal defects (Terdermis) without fibrin glue was developed. Eardrum perforations were successfully closed in 71.4% of all cases (63 ears) after the initial treatment. Neither skin incision nor the use of temporal fascial grafts was necessary in this method. The merit of the method is that there is no possibility of blood infection because no blood materials are used.

Adolescent↗
PubMed2000

Band-suppressed restoration of X-ray images blurred by body movement.

The restoration of X-ray images that have been blurred due to body movement are discussed. The observation system for these images is described using a mathematical model, and several restoration filters composed of a series of such models are proposed. These filters restore band-suppressed approximations of the original images. In addition, redundancy is introduced into these restoration filters in order to suppress additive noise. These filters are expanded to be applicable not only to parallel translations, but also to rotations by coordinate transformation. The proposed methods are applied to blurred X-ray images of a bone model of the elbow joint. The parameters of the restoration filter are estimated using a marker attached to the subject as a reference signal.

Artifacts↗
PubMed2000

[Correlation between pyrimidine nucleoside phosphorylase (PyNPase) and clinicopathological factors in patients with gastric cancer].

Pyrimidine nucleoside phosphorylase (PyNPase) is a general term for enzymes which phosphorolyse pyrimidine class nucleosides; convert 5'-deoxy-5-fluorouridine (5'-DFUR), a fluoropyrimidine class anticancer drug, to an active type of 5-fluorouracil (5-FU); and demonstrate higher concentrations in tumor tissue. These findings have attracted attention from the standpoint of drug delivery systems. With regard to immunohistochemical staining studies, PyNPase expression correlated with cancer proliferation and metastasis. However, few have shown a relation between PyNPase assay and prognosis. We measured PyNPase value in tumor tissue of operative specimens from 60 gastric cancer patients. The results showed that the PyNPase value in tumor tissue was significantly higher (1.9 times) than in normal mucosa. There was no correlation between the PyNPase level in tumor tissue and clinicopathologic factors. However, many patients with relatively early gastric cancer had high enzyme levels, indicating that PyNPase may influence cancer proliferation and metastasis as well as prognosis. By detecting such a factor as PyNPase, and clinically applying the results, 5'-DFUR is promising for the treatment of patients with respect to prognosis.

Adult↗
PubMed2000

[A noteworthy case of postoperative liver metastasis from gastric cancer which responded well to UFT therapy].

A 66-year-old male underwent partial gastrectomy (resection of the pyloric side of the stomach) at another hospital on the basis of a diagnosis of gastric cancer (Fig. 1). Five months later, his CEA level began to rise. At that time, multiple liver metastases were detected by ultrasonography and CT scans. The patient received oral UFT therapy (400 mg/day) at our hospital. A reduction in CEA was observed 63 days after the start of this therapy. A judgment of CR (complete response) was made after 4 months of the therapy. At present, 2 years and 4 months after UFT was first administered, the patient shows no signs of tumor recurrence. This case is noteworthy since there has been no previous report of a case where UFT showed a high efficacy in treating liver metastasis after surgical resection of gastric cancer.

Adenocarcinoma↗
PubMed1999

The integrin alpha(9)beta(1) binds to a novel recognition sequence (SVVYGLR) in the thrombin-cleaved amino-terminal fragment of osteopontin.

The integrin alpha(9)beta(1) mediates cell adhesion to tenascin-C and VCAM-1 by binding to sequences distinct from the common integrin-recognition sequence, arginine-glycine-aspartic acid (RGD). A thrombin-cleaved NH(2)-terminal fragment of osteopontin containing the RGD sequence has recently been shown to also be a ligand for alpha(9)beta(1). In this report, we used site-directed mutagenesis and synthetic peptides to identify the alpha(9)beta(1) recognition sequence in osteopontin. alpha(9)-transfected SW480, Chinese hamster ovary, and L-cells adhered to a recombinant NH(2)-terminal osteopontin fragment in which the RGD site was mutated to RAA (nOPN-RAA). Adhesion was completely inhibited by anti-alpha(9) monoclonal antibody Y9A2, indicating the presence of a non-RGD alpha(9)beta(1) recognition sequence within this fragment. Alanine substitution mutagenesis of 13 additional conserved negatively charged amino acid residues in this fragment had no effect on alpha(9)beta(1)-mediated adhesion, but adhesion was dramatically inhibited by either alanine substitution or deletion of tyrosine 165. A synthetic peptide, SVVYGLR, corresponding to the sequence surrounding Tyr(165), blocked alpha(9)beta(1)-mediated adhesion to nOPN-RAA and exposed a ligand-binding-dependent epitope on the integrin beta(1) subunit on alpha(9)-transfected, but not on mock-transfected cells. These results demonstrate that the linear sequence SVVYGLR directly binds to alpha(9)beta(1) and is responsible for alpha(9)beta(1)-mediated cell adhesion to the NH(2)-terminal fragment of osteopontin.

Amino Acid Sequence↗
PubMed1999

Cellular localization of adenosine A1 receptors in rat forebrain: immunohistochemical analysis using adenosine A1 receptor-specific monoclonal antibody.

Monoclonal antibodies were generated against the adenosine A1 receptor (A1R) purified from rat brain. In immunoblot analyses of purified or partially purified A1R preparations from rat brain, these antibodies recognized a solitary band, the size of which corresponded to that expected for A1R. These antibodies recognized not only the native form of A1R but also the deglycosylated form of A1R. Immunocytochemical analysis of Chinese hamster ovarian cells that were transfected stably with rat A1R cDNA showed that their cell bodies were stained intensely by these antibodies, whereas nontransfected Chinese hamster ovarian cells were not. These antibodies detected the A1R naturally present in the DDT(1)( )MF-2 smooth muscle cells. One of these antibodies (the 511CA antibody) was then used to examine the immunohistochemical distribution of A1Rs in rat forebrain. On light microscopy, A1R immunoreactivity was observed in the cerebral cortex, septum, basal ganglia, hippocampal formation, and thalamus. However, in some regions of the forebrain, regional differences in staining intensity were found as follows: In the cerebral cortex, the strongest immunoreactivity was found in the large pyramidal neurons of layer V. This immunoreactivity was detected in the pyramidal cell bodies, dendrites, and axon initial segments. In the hippocampus, A1R immunoreactivity was detected mainly in the stratum pyramidale. The pyramidal cells in fields CA2-CA3 of the hippocampus were stained more intensely or more clearly than those in field CA1 or the dentate gyrus. More intense A1R immunoreactivity of the apical dendrites was detected in field CA2 compared with other hippocampal fields and the dentate gyrus. Many interneurons of the hippocampus were stained by the 511CA antibody. The subcellular distribution of A1Rs in the forebrain was examined by using a digital deconvolution system and electron microscopy. In the cerebral cortex, the view obtained by removing the background haze by deconvolution revealed that the immunofluoresence-labeled A1Rs were distributed on the surfaces of the cell bodies and dendrites and in the cytoplasm of layer V neurons as small spots. In field CA1, immunoreactivity was detected in the areas surrounding pyramidal cells. Electron microscopy revealed the presence of A1R-immunoreactive products in both the presynaptic terminals and the postsynaptic structures. The specific cellular distribution of A1Rs is consistent with the physiological premise that endogeneously released adenosine exerts control over the excitability of forebrain neurons at both presynaptic and postsynaptic sites through A1Rs.

Animals↗
PubMed1999

Enteral nutrition prevents bacterial translocation but does not improve survival during acute pancreatitis.

OBJECTIVE: To evaluate the effect of enteral nutrition (EN) in attenuating bacterial and/or endotoxin translocation, maintaining immune responsiveness, and improving outcome in early acute pancreatitis (AP) in Wistar male rats. DESIGN: Acute pancreatitis was induced in rats receiving total parenteral nutrition (TPN) (AP/TPN group) (n=34) and EN (AP/EN group) (n=35) by pressure injection of 1% deoxycholate into the biliopancreatic duct (0.6 mg/kg of body weight). Rats in the sham/TPN and sham/EN groups (n=10 each) underwent laparotomy without induction of AP. Catheters for TPN and EN were placed into the external jugular vein and jejunum, respectively. Rats were infused with Ringer lactate solution for 48 hours followed by TPN in the AP/TPN and sham/TPN groups, and EN in the AP/EN and sham/EN groups until day 7. The fluid volume and energy (calories) intake were similar in all groups. SETTING: Medical school research laboratory. MAIN OUTCOME MEASURES: Survival, blood endotoxin level, villus height, 5-bromo-2'-deoxyuridine (BrdU) uptake in the jejunum and ileum, bacterial culture of mesenteric lymph nodes, and CD4/CD8 ratio of T cells in mesenteric lymph nodes, spleen, and peripheral blood. RESULTS: There was no difference in survival and pancreatic healing between the AP/TPN and AP/EN groups. Colony-forming units of the mesenteric lymph nodes and the endotoxin level were significantly lower in the AP/EN group than in the AP/TPN group (P<.05). Villus height and BrdU intake was significantly higher in the AP/EN group than in the AP/TPN group (P<.05). The CD4/CD8 ratio of T cells in spleen and peripheral blood was higher in the AP/EN group than in the AP/TPN group (P<.05), whereas there was no difference in mesenteric lymph nodes. CONCLUSIONS: Jejunal administration of EN is well tolerated in early AP, maintains immune responsiveness and gut integrity, and reduces bacterial and/or endotoxin translocation. However, compared with TPN, EN does not improve outcome. These results suggest that factors other than bacterial and/or endotoxin translocation may be responsible for mortality in this rat model of early AP. However, additional studies of both early bacterial and/or endotoxin translocation and late assessment of outcome are indicated.

Acute Disease↗
PubMed1999

The prognostic significance of lymph node metastasis and intrapancreatic perineural invasion in pancreatic cancer after curative resection.

To investigate the prognostic factors of pancreatic cancer, a retrospective analysis of 193 patients who underwent curative resection was conducted. Of the 193 patients, 38 (20%) survived for more than 5 years, the 5-year survival rates for stages I, II, II, and IV disease being 41%, 17%, 11%, and 6%, respectively. According to a multivariate analysis, lymph node metastasis, intrapancreatic perineural invasion, and portal vein invasion were significant prognostic factors. Subsequently, a subgroup analysis concerning nodal metastasis and intrapancreatic perineural invasion was performed in 126 patients with records of these histological findings. In the group of patients without nodal metastasis, the 5-year survival rate for those without perineural invasion was 75%, whereas that for those with perineural invasion was 29%, the difference in survival of these subgroups being significant (P < 0.02). In the group of patients with nodal metastasis, the 5-year survival rate for those without perineural invasion was 17%, while that for those with perineural invasion was 10%. The most favorable 5-year survival of 89% was observed in the subgroup of patients with stage I disease without perineural invasion. Thus, pancreatic adenocarcinoma categorized by the combination of these independent types of biological behavior showed 5-year survival rates ranging from very high to low, indicating that these two factors play an important role in the prognosis of this disease.

Adenocarcinoma↗
PubMed1999

Combined diltiazem and lidocaine reduces cardiovascular responses to tracheal extubation and anesthesia emergence in hypertensive patients.

PURPOSE: Hypertensive patients exhibit exaggerated cardiovascular responses to tracheal extubation. This study was undertaken to compare the efficacy of combined diltiazem and lidocaine with each drug alone in suppressing the hemodynamic changes during tracheal extubation. METHODS: Sixty hypertensive patients (ASA II), defined as systolic blood pressure > 160 mmHg and/or diastolic blood pressure > 95 mmHg (WHO), undergoing elective orthopedic surgery received, in a randomized, double-blind manner, 0.2 mg x kg(-1) diltiazem, 1.0 mg x kg(-1) lidocaine, or 0.2 mg x kg(-1) diltiazem plus 1.0 mg x kg(-1) lidocaine (n=20 of each) i.v. before tracheal extubation. Changes in heart rate (HR), mean arterial pressure (MAP) and rate-pressure product (RPP) were measured before and after tracheal extubation. RESULTS: Hemodynamic changes during tracheal extubation were less in patients receiving diltiazem plus lidocaine than in those receiving diltiazem or lidocaine as a sole medicine (RPP; 10322 +/- 1674 (combined) vs 11532 +/- 1802 (diltiazem), 15388 +/- 2050 (lidocaine), mean +/- SD, P < 0.05). CONCLUSION: Combined diltiazem and lidocaine is more effective prophylaxis than diltiazem or lidocaine alone for attenuating the cardiovascular responses to tracheal extubation and emergence from anesthesia in hypertensive patients.

Aged↗